We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Evaluation of Warm-Rain Microphysical Parameterizations in Mesoscale Simulations of the Cloudy Marine Boundary Layer.
- Authors
Nelson, Kevin J.; Mechem, David B.; Kogan, Yefim L.
- Abstract
Several warm-rain microphysical parameterizations are evaluated in a regional forecast model setting (using the Naval Research Laboratory's Coupled Ocean-Atmosphere Mesoscale Prediction System) by evaluating how accurately the model is able to represent the marine boundary layer (MBL). Cloud properties from a large suite of simulations using different parameterizations and concentrations of cloud condensation nuclei (CCN) are compared to ship-based observations from the Variability of the American Monsoon Systems (VAMOS) Ocean-Cloud-Atmosphere-Land Study-Regional Experiment (VOCALS-REx) field campaign conducted over the southeastern Pacific (SEP). As in previous studies, the simulations systematically underestimate liquid water path and MBL cloud depth. On the other hand, the simulations overestimate precipitation rates relative to those derived from the scanning C-band radar on board the ship. Most of the simulations exhibit a diurnal cycle, although details differ somewhat from a recent observational study. In addition to direct comparisons with the observations, the internal microphysical consistency of simulated MBL cloud properties is assessed by comparing simulation output to a number of observationally and theoretically derived scalings for precipitation and coalescence scavenging. Simulation results are broadly consistent with these scalings, suggesting COAMPS is behaving in a microphysically consistent fashion. However, microphysical consistency as defined in the analysis is highly dependent upon the horizontal resolution of the model. Excessive depletion of CCN from large coalescence processing rates suggests the importance of parameterizing a source term for CCN or imposing some form of fixed, climatological background CCN concentration.
- Subjects
MESOSCALE convective complexes; STRATUS clouds; CLOUD condensation nuclei; METEOROLOGICAL precipitation; ATMOSPHERIC models
- Publication
Monthly Weather Review, 2016, Vol 144, Issue 6, p2137
- ISSN
0027-0644
- Publication type
Article
- DOI
10.1175/MWR-D-15-0266.1